Browse Topic: Braking systems

Items (5,461)
Verifying training datasets in vision-based vehicle safety applications is crucial to understanding the potential limitations of detection capabilities that may result in a higher safety risk. Vision-based pedestrian safety applications with crash avoidance technologies rely on prompt detection to avoid a crash. This research aims to develop a verification process for vulnerable road user safety applications with vision-based detection functionalities. It consists of reviewing the application’s safety requirements, identifying the target objects of detection in the operational design domain and pre-crash scenarios, and evaluating the safety risks qualitatively by examining the training dataset based on the results of pre-crash scenarios classification. As a demonstration, the process is implemented using open-source pedestrian tracking software, and the pre-crash scenarios are classified based on the trajectories of pedestrians in an example training dataset used in a pedestrian
Hsu, Chung-Jen
A serious problem of public healthcare around the world is the number of road vehicle accidents, every year almost 1,3 million people die and approximately 20 to 50 million people suffer a non-fatal accident because of a road vehicle accident [1]. As a result of that, in 2021 the World Health Organization stated the “The Second Decade of Action for Road Safety”, which the goal is to prevent at least 50% of deaths and injuries due traffic by 2030. To achieve this goal, the automobile companies have invested in technology and products that can enhance vehicle safety. Despite exist some control systems able to reduce roll, and consequently the roll over, such as active suspension, semi-active suspension, and stability control systems, none of them have as main purpose reduce the number of rollovers. The following study aims to examine the effects of an active anti roll bar, to improve the vehicle dynamics during corners and reduce the risk of a rollover by reducing the roll of the sprung
Gomes, Pedro CarvalhoTeixeira, Evandro Leonardo SilvaMorais, Marcus Vinicius GirãoFortaleza, Eugenio Liborio FeitoraSantos Gioria, Gustavo
Electric vehicles represent a shift towards sustainability in the automotive industry, with the Brake-by-Wire (BBW) system as an innovation to enhance safety, and performance. This study proposes an electromagnetic BBW system for Formula SAE vehicles, optimizing an electromagnet with a genetic algorithm as the actuator. Through a selection process from a million individuals, the system was modeled. Integrated with electric motors using CarMaker® software, the optimized electromagnet surpassed the minimum required force of 228.08 N without reaching its nominal current of 12.5 A, achieving a force of 231.1 N for 150 W power, indicating an energy efficiency of 0.706 N/Watt. The system also exhibited a response time of 17.92ms for an 80 bar increase, 1.52 times better than compared systems. Simulation under varying braking intensities demonstrated dynamic behavior, with settling times for slow, moderate, and sharp braking at 193 ms, 62 ms, and 21 ms, respectively. Efficiency during
Salgado, Vinícius Batista AlvesGomes, Deilton GonçalvesAndrade Lima, Cláudio
The SAE Formula prototypes are developed by students, where in the competition, various aspects of project definitions are evaluated. Among the factors evaluated for scoring is the braking system, in which the present work aims to present the development and design of the braking system of a vehicle, prototype of Formula SAE student competition. As it is a project manufactured mostly by students, where the chassis, suspension system, electrical, transmission and powertrain are developed, it is important to first pass the static and safety tests, where the brakes of the four wheels are tested during deceleration at a certain distance from the track. To enable such approval and also to demonstrate, for the competition judges, the veracity of the system’s sizing, all the parameters and assumptions of the choice of the vehicle’s braking system are presented, thus ensuring their reliability, efficiency and safety. Using drawing and simulation software such as SolidWorks and Excel for
Gomes, Lucas OlenskiGrandinetti, Francisco JoséMartins, Marcelo SampaioSouza Soares, Alvaro ManoelReis de Faria Neto, AntônioCastro, Thais SantosAlmeida, Luís Fernando
Single lane changing is one of the typical scenarios in vehicle driving. Planning an appropriate lane change trajectory is crucial in autonomous and semi-autonomous vehicle research. Existing polynomial trajectory planning mostly uses cubic or quintic polynomials, neglecting the lateral jerk constraints during lane changes. This study uses seventh-degree polynomials for lane change trajectory planning by considering the vehicle lateral jerk constraints. Simulation results show that the utilization of the seventh-degree method results in a 41% reduction in jerk compared to the fifth-degree polynomial. Furthermore, this study also proposes lane change trajectory schemes that can cater to different driving styles (e.g., safety, efficiency, comfort, and balanced performance). Depending on the driving style, the planned lane change trajectory ensures that the vehicle achieves optimal performance in one or more aspects during the lane change process. For example, with the trajectory that
Lai, FeiHuang, Chaoqun
With the technology of electronic chassis control systems of automobile is widely used, the functional interaction between brake system and the other electronic systems may lead to brake boost degradation. Therefore, it is necessary to find out brake boost degradation events in the quite large number of driving scenarios. To solve the difficulty of thoroughly and quickly searching for brake boost degradation conditions in the large number of driving scenarios, based on Mechatronic-Hardware-In-the-Loop (M-HIL) technology, this paper constructs an electrical chassis system M-HIL bench to verify the function and performance of the electronic brake control system under actual chassis system conditions. To search and locate the brake boost degradation conditions rapidly and enhance the searching efficiency of levels boundary of affecting factors for brake boost degradation, firstly, based on pair-wise coverage combinatorial testing, brake boost degradation occurrence rate is estimated and
Guo, XiaotongLi, LunChen, ZhichengZhang, LiliangYan, LupingWang, WeiZh, Bing
The traditional braking system has been unable to meet the redundant safety requirements of the intelligent vehicle for the braking system. At the same time, under the change of electrification and intelligence, the braking system needs to have the functions of braking boost, braking energy recovery, braking redundancy and so on. Therefore, it is necessary to study the redundant braking boost control of the integrated electro-hydraulic braking system. Based on the brake boost failure problem of the integrated electro-hydraulic brake system, this paper proposes a redundant brake boost control strategy based on the Integrated Brake Control system plus the Redundant Brake Unit configuration, which mainly includes fault diagnosis of Integrated Brake Control brake boost failure, recognition of driver braking intention based on pedal force, pressure control strategy of Integrated Brake Control brake boost and pressure control strategy of Redundant Brake Unit brake boost. The designed control
Dexing, LaoLuping, YanQinghai, SuiLong, CaoShang, GaoZhigang, ChenMingxing, RenZhicheng, Chen
This SAE Recommended Practice is derived from common methods used within the industry and is not intended to validate a given design or configuration. This SAE Recommended Practice applies to vehicles below 4540 kg of gross vehicle weight rating
Brake NVH Standards Committee
This study investigates into the mechanical performance of load vehicle brake liners that have been enhanced with nanomaterials, employing Finite Element Analysis (FEA). The analysis involves a detailed investigation of structural, thermal, and wears characteristics to evaluate the overall performance of the brake liners. This research aimed to reduce the stress and pressure exerted on vehicle brakes during braking by conducting a comprehensive stress analysis of the braking system. Finite Element Analysis serves as a powerful tool for simulating and assessing the behavior of complex structures under varying conditions. In this research, the study employs FEA techniques to model and analyze the load vehicle brake liners, considering the incorporation of nanomaterial’s, with a special emphasis on materials like Al2O3.The aim is to gain a profound understanding of how these nanomaterial’s influence and improve the mechanical aspects of the brake liners
Kumar, N. MathanThillikkani, S.Kannan, S.Soundararajan, S.Bharti, Kundan
This SAE standard specifies a method for testing and measuring a normalized elastic constant of brake pad assemblies using ultrasound. This document applies to disc brake pad assemblies and its coupons or segments used in road vehicles
Brake Linings Standards Committee
This SAE Recommended Practice establishes methods to determine grade parking performance with respect to: a Ability of the parking brake system to lock the braked wheels. b The vehicle holding or sliding on the grade, fully loaded or unloaded. c Applied manual effort. d Unburnished or burnished brake lining friction conditions. e Down and up grade directions
Truck and Bus Brake Systems Committee
Heavy-duty vehicles, particularly those towing higher weights, require a continuous/secondary braking system. While conventional vehicles employ Retarder or Engine brake systems, electric vehicles utilize recuperation for continuous braking. In a state where HV Battery is at 100% of SOC, recuperated energy from vehicle operation is passed on to HPR and it converts electrical energy into waste heat energy. This study focuses on identification of routes which are critical for High Power Brake Resistors (HPRs), by analyzing the elevation data of existing charging stations, the route’s slope distribution, and the vehicle’s battery SOC. This research ultimately suggests a method to identify HPR critical vehicle operational routes which can be useful for energy efficient route planning algorithms, leading to significant cost savings for customers and contributing to environmental sustainability
Thakur, ShivamSalunke, OmkarAmbuskar, MandarPandey, Lokesh
Brake disc temperature is a critical factor influencing the performance and wear characteristics of braking systems in automobiles. Hence it is very important to optimize the correlation of brake disc temperature prediction with test. In this study critical parameters of Brake Disc temperature evaluation are identified, and algorithm is used to optimize the critical parameters to achieve the correlation of prediction with experiment data. Through a series of controlled experiments and simulations, disc temperatures are monitored under different braking conditions and simultaneously input parameters for prediction are optimized to achieve the correlation. Statistical methods were applied to evaluate the observed correlations and to model the predictive behavior of brake disc temperatures. Finally, A front-loading tool is developed to optimize the brake disc keeping target thermal capacity via algorithm. The findings of this study are expected to contribute to the enhancement of brake
Negi, Ayush SinghKochhar, Raman
Hydro-pneumatic suspension is widely used because of its desirable nonlinear stiffness and damping characteristics. However, the presence of parameter uncertainties and high nonlinearities in the system, lead to unsatisfactory control performance of the traditional controller in practical applications. In response to this challenge, this paper proposes a novel stability control method for active hydro-pneumatic suspension (AHPS). Firstly, a nonlinear mathematical model of the hydro-pneumatic suspension, considering the seal friction, is established based on the hydraulic principle and the knowledge of Fluid dynamics. On the basis of the established hydro-pneumatic suspension nonlinear model, a vehicle dynamics model is established. Secondly, an active disturbance rejection sliding mode controller (ADRSMC) is designed for the vertical, roll, and pitch motions of the sprung mass. The lumped disturbance caused by the model nonlinearities and uncertainties is estimated by the extended
Niu, ChangshengLiu, XiaoangJia, XingGong, BoXu, Bo
The SAE J2923 procedure is a recommended practice that applies to on-road vehicles with a GVWR below 4540 kg equipped with disc brakes
Brake Dynamometer Standards Committee
Komatsu introduced its first battery-electric load-haul-dump (LHD) machine, the WX04B, at the MINExpo tradeshow in September. The WX04B is designed specifically for narrow vein mines in underground hard rock mining operations. Komatsu is pairing the electric LHD with its new OEM-agnostic 150-kW battery charger that was also revealed in Las Vegas. The 4-tonne WX04B LHD features what Komatsu claims is best-in-class energy density, offering up to four hours of runtime on a single charge. The Li-ion NMC (nickel-manganese-cobalt) battery from Proterra has a capacity of 165 kWh and nominal voltage of 660 V. Fewer charge cycles are needed compared to competitors, the company claims, which helps to maximize operational efficiency and minimize downtime. Proterra and Komatsu began their collaboration on the LHD's H Series battery system in 2021, long before Komatsu's acquisition of American Battery Solutions (ABS) in December 2023
Gehm, Ryan
This recommended practice shall apply to all on-highway trucks and truck-tractors equipped with air brake systems and having a GVW rating of 26 000 lb or more
Truck and Bus Human Factors Committee
This SAE Recommended Practice provides instructions and test procedures for measuring air consumption of air braked vehicles equipped with Antilock Brake Systems (ABS) used on highways
Truck and Bus Brake Systems Committee
ABSTRACT This paper provides detail of the system architecture and systems engineering process utilized by AM General to develop a new stability control system that satisfies all military and federal safety requirements for wheeled, light tactical vehicles
Tackett, WendellClark, Mark
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